A method for manufacturing an extraordinary magnetoresistive sensor (EMR sensor) having reduced size and increased resolution is described. The sensor includes a plurality of electrically conductive leads contacting a magnetically active layer and also includes an electrically conductive shunt structure. The electrically conductive leads of the sensor and the shunt structure can be formed in a common photolithographic masking and etching process so that they are self aligned with one another. This avoids the need to align multiple photolithographic processing steps, thereby allowing greatly increased resolution and reduced lead spacing. The EMR sensor can be formed with a magnetically active layer that can be close to or at the air bearing surface (ABS) for improved magnetic spacing with an adjacent magnetic medium of a data recording system.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for manufacturing an extraordinary magnetoresistive sensor (EMR sensor), comprising: providing a substrate; growing a semiconductor heterostructure on the substrate; forming a first mask structure over the heterostructure; performing a first material removal process to remove portions of the semiconductor heterostructure that are not protected by the first mask structure to form a mesa structure; removing the first mask structure; forming a second mask structure, the second mask structure having a plurality of lead defining openings and a shunt defining opening; performing a second material removal process to remove portions of the semiconductor heterostructure that are exposed through the lead defining openings and the shunt defining openings; and depositing an electrically conductive material.
2. The method as in claim 1 , wherein the first and second material removal processes comprise etching.
3. The method as in claim 2 , wherein the hetrostructure includes first, second and third semiconductor layers, each having a bandgap, the second semiconductor layer being sandwiched between the first and third semiconductor layer and having the bandgap that is smaller than that of the first and third semiconductor layers.
4. A method as in claim 1 wherein the lead defining openings overlap the mesa structure whereby the second material removal process forms notches in the mesa structure.
5. A method for manufacturing an extraordinary magnetoresistive (EMR) sensor, comprising: providing a substrate; growing a semiconductor heterostructure over the substrate; forming a mask structure over the semiconductor heterostructure, the mask structure having a plurality of lead defining openings, and a shunt defining opening; performing a material removal process to remove portions of the semiconductor heterostructure not protected by the mask structure; and depositing an electrically conductive material.
6. The method as in claim 5 , further comprising: after growing the semiconductor heterostructure and before forming the mask structure, depositing a thin layer of electrically insulating material over the semiconductor heterostructure.
7. The method as in claim 6 further comprising, before growing the semiconductor heterostructure, depositing a selectively etchable buffer layer on the substrate; and after depositing the electrically insulating material, performing an etching process to remove at least a portion of the buffer layer to lift off the EMR sensor from the substrate.
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December 17, 2010
May 1, 2012
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